The activities of Dr. Keen’s research group are currently focused in two areas; the investigation of the influence of maternal diet on the risk for pregnancy complications (maternal, conceptus, and fetal) and the influence of diet on the risk for age-related chronic diseases. Regarding the influence of diet on embryonic and fetal development, his group has been studying the acute and long-term consequences of micronutrient deficiencies on embryonic and fetal development for almost three decades. The majority of their efforts have been centered on the characterization of the effects of primary and secondary zinc and copper deficiencies. Recently this work has been focused on the effects of these deficiencies on oxidative stress in the conceptus, and its consequences, particularly with respect to the vascular system and the developing brain. Regarding the influence of diet and chronic disease, during the past decade his group’s work has been centered on the study of dietary factors that influence the risk for vascular disease. A current hypothesis in the laboratory is that a significant part of the positive cardiovascular health benefits associated with plant food rich diets can be attributed to their flavanol content.